1. Field of the Invention
The present invention relates to a solenoidal coil used for measuring nuclear magnetic resonance (NMR) and to an NMR signal acquisition device on which the solenoidal coil is mounted, and more particularly to a solenoidal coil for an NMR signal for use as a transmitter-receiver coil, a transmitter coil, or a receiver coil and to an NMR signal acquisition device on which solenoidal coil is mounted.
2. Description of the Related Art
A saddle coil, a birdcage coil, or a solenoidal coil is used on an NMR signal measuring device to apply a high frequency magnetic field to a sample to be measured and to acquire the NMR signal from the sample. When a high frequency magnetic field is applied to a sample, the magnetic field intensity is required to be homogeneous in the sample space.
Although a multiple-turn coil is used to increase the sensitivity of a solenoidal coil, the magnetic field homogeneity in a high frequency magnetic field tends to decrease because the sensitivity area extends cylindrically. JP-A-2002-345777 (abstract) discloses a technology for increasing the magnetic field homogeneity at transmission time by flowing an equal amount of RF (Radio Frequency) current in each loop of the coil at transmission time.
As described above, there is a problem that the magnetic field homogeneity of a solenoidal coil in a high frequency magnetic field is low.